This is a great place to enjoy a mountain hike and the outdoors for a few hours. From the exit, it's a beautiful 10-mile drive up a forested hanging valley to the glacier trailhead. The glacier, technically a large snowfield compacted in a mountain saddle at the timberline, is thought to be the southernmost glacier in the United States. During drought years it all but vanishes; a wet winter creates a wonderful Ice Age playground throughout the following summer. Most visitors are content to make the steep ¾-mile hike on a rock-strewn path up to the base of the glacier to admire the snowfield and sparkling sapphire lake. The intrepid hiker, with the right type of gear, can climb up the rocky right-hand side of the snowfield to a plateau less than a mile above for sweeping views of the Continental Divide. Because of its proximity to Denver, St. Mary's Glacier is a popular weekend getaway for summer hikers, snowboarders, and skiers. There are two pay parking lots with about 140 spaces between them; the cost is $5 per vehicle per day, with restrooms and trash facilities available at both. Don't look for a St. Mary's Glacier sign on I–70; it reads "St. Mary's Alice" to refer to the nearby ghost towns.